The estimated beta or low-energy gamma doses are listed in Table 1 as
"shallow" doses, in keeping with the concepts set forth in ICRU 25 (C076).
The energy deposited by 90s, in tissue is predominantly within the first
centimeter (HA75).
The integral 30-year external doses due to betas or
low-energy gammas vary from 1/4 to 1/2 of the total external integral doses,
depending on the living pattern chosen.
The variability is due to differences
in 137 ¢6) 9c, and 5, soil concentrations as a function of time on
different islands.
The integral external doses in Table 1 include no
assumptions about modifications which could be made to reduce external dose
rates; remedial actions, such as providing gravel around villages or plowing
the islands, could very substantially reduce the external shallow dose
contribution.
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